CN105784336B - A kind of transmission of optical fibre device and reflecting properties test device and method - Google Patents

Abstract

The invention provides a device and method for simultaneously testing the transmission and reflection properties of an optical fiber device. Inject broad-spectrum light into the device under test to generate two-way optical signals that can reflect its transmission and reflection performance, and inject the optical signal into the optical coherent domain. In the structure, the common delay component is used for scanning, the two optical signals are measured, and the transmission and reflection characteristics of the optical fiber device to be tested are obtained at the same time. In the case of using the same light source and the same delay component, the transmission and reflection performance test device of optical fiber devices can accurately measure the characteristic parameters of the device under test such as polarization performance, dispersion characteristics, loss characteristics, and coherent spectral characteristics. The invention has the advantages of high integration degree, complete test parameters, anti-electromagnetic interference, simple device composition, etc., and can be widely used in high-precision measurement and analysis of the performance of optical devices such as polarization-maintaining optical fibers and integrated waveguide modulators.

Description

Device and method for testing transmission and reflection performance of optical fiber device

technical field

The invention relates to a performance testing device of an optical fiber device. The invention also relates to a performance testing method of the optical fiber device.

Background technique

Due to the ability of distributed optical fiber sensing technology to obtain the measured distribution information of the device at the same time, an important application of white light interferometry principle and technology is in the high-precision testing and evaluation of optical waveguides and optical fiber devices. It has been developed rapidly. Among them, optical coherent domain polarization measurement technology (OCDP) and optical low coherence domain reflection technology (OLCR) are high-precision distributed measurement technologies for measuring the transmission characteristics and reflection characteristics of devices, respectively.

Optical Low Coherence Domain Reflectometry (OLCR) is a distributed measurement technology based on the backscattering of light for sensing and detection. It also uses a wide-spectrum light source to drive an interferometer, which is suitable for the quantification of weak reflection information inside optical devices and waveguides. Measurement.

Optical coherent domain polarization measurement technology (OCDP) is based on the principle of wide-spectrum optical interference. Optical path compensation is performed through a scanning optical interferometer to achieve interference between different polarization modes. It can accurately measure the spatial position of polarization crosstalk and the intensity of polarization coupling signals. The measurement and analysis of the optical polarization device, and then obtain important parameters such as extinction ratio and beat length of the optical polarization device.

Distributed optical fiber sensing technology can truly describe the transmission and reflection behavior of signal light in the optical fiber optical path, and is especially suitable for testing and evaluating optical fiber devices, components, and high-precision and ultra-high-precision interferometric optical fiber sensing optical paths. It has the advantages of simple structure, high spatial resolution, large measurement range, and high measurement sensitivity. For example, the polarization-sensitive PS-OLCR developed by Italian Melloni A et al., that is, the polarization-selective PS-OLCR is added on the basis of the traditional transmission OLCR. Optical low-coherence domain reflectometer; a kind of all-fiber measurement system (US20110277552, Measuring Distributed) for distributed polarization crosstalk measurement in polarization-maintaining optical fiber and optical birefringent material disclosed by Yao Xiaotian et al. of General Photonics Corporation of the United States Polarization Crosstalk in Polarization Maintaining Fiber and Optical Birefringent Material).

In the test of the device, when OLCR or OCDP is used alone, only the reflection or transmission characteristics of the beam in the device can be obtained. In order to obtain more detailed information of the device, it is necessary to study its reflection and transmission characteristics at the same time. In addition, in order to weaken the impact of external interference on the test, the simultaneous measurement of the reflection and transmission characteristics of the device is even more critical. It is of great significance to build a distributed device that can measure the reflection and transmission characteristics of the device at the same time for the test of the comprehensive characteristics of the device.

Contents of the invention

The object of the present invention is to provide a high-precision, stable and reliable testing device for the transmission and reflection performance of optical fiber devices. The purpose of the present invention is also to provide a method for testing the transmission and reflection performance of the optical fiber device.

The transmission and reflection performance testing device of the optical fiber device of the present invention comprises a wide-spectrum light source 501, a transmission performance testing structure 530 of the optical coherent domain polarization measurement technology (OCDP), a reflection performance testing structure 540 of the optical low coherence reflection technology (OLCR), and a detection system. With the signal recording device 550, the device under test part 560, the wide-spectrum light source 501 injects light beams into the device under test part 560, the device under test 511 in the device under test part 560 generates a transmitted beam 560a and a reflected beam 560b respectively, and the transmitted beam 560a Inject into the transmission performance test structure 530 of the optical coherent domain polarization measurement technology, inject the reflected light beam 560b into the reflection performance test structure 540 of the optical low-coherence reflection technology, and use the common delay component 519 to perform simultaneous scanning, and the interference light in the two structures The signal is measured, and finally the transmission and reflection characteristics of the optical fiber device under test are obtained simultaneously.

The transmission and reflection performance testing device of the optical fiber device of the present invention may also include:

1. The transmission performance test structure 530 of the optical coherent domain polarization measurement technology includes: after the transmitted light beam 560a is analyzed by the first analyzer 515, it is divided into two beams by the first coupler 516, and injected into the optical coherent domain polarization measurement technology respectively. In the scanning arm 524 and the transmission arm 525 of the transmission performance test structure, the scanning arm is connected to the first collimator lens 518 through the first circulator 517, scanned and reflected by the common delay component 519, and the last two beams of light are coupled in the second The detector 521 interferes, and the interference signal is received through the first detector 522 and the second detector 523 .

2. The reflection performance test structure 540 of the optical low-coherence reflection technology includes: the wide-spectrum light source 501 is divided into two beams through the third coupler 502, and one beam is transmitted by the transmission arm 503 of the reflection performance test structure of the low-coherence reflection technology. 2 The circulator 509 enters the device under test 511, and the reflected light beam 560b passes through the second circulator 509 and the second polarizer 510 to continue to propagate in the transmission arm 503 of the reflective performance test structure of the low-coherence reflection technology; the other beam is used as a reference light Transmitted in the scanning arm 508 of the reflection performance test structure of the low-coherence reflection technology, the scanning arm is connected to the second collimator lens 506 through the third circulator 507; the last two beams of light interfere at the fourth coupler 512, and pass through the third detector The detector 513 and the fourth detector 514 receive the interference signal.

3. The detection and signal recording device 550 is composed of a signal processing unit 551 and a computer terminal 552 .

The testing method of the transmission and reflection performance testing device based on the optical fiber device of the present invention comprises:

(1) measure the length l _W of the device under test 511, calculate the maximum reflected optical path difference S _W1 of the device under test 511, S _W1 = l _W × n _W , and n _W is the refractive index of the device under test 511;

(2) Under the premise of not calculating the delay line scanning optical path S, measure the respective total optical paths L _cr and L _cm of the scanning arm 508 and the transmission arm 503 in the reflective performance test structure 540 of the optical low coherence reflection technology;

(3) judge whether the scanning optical path range S introduced by the common delay component 519 satisfies S>S _W1 and S>L _cm -L _cr , if satisfied, skip step (4) and carry out the measurement of step (5);

(4) If the condition is not satisfied, then re-intercept the length of the two-arm optical fiber of the reflection performance test structure 540 of the optical low coherence reflection technology, so that it meets the required conditions in step (3);

(5) Test the lengths of the front polarization-maintaining fiber s3 and the rear polarization-maintaining fiber s4 of the device under test 511 respectively, which are denoted as l _Wi and l _Wo , and calculate the optical path difference _SL introduced by the fast and slow axes of the polarization-maintaining fiber, _SL =(l _Wi +l _Wo )×Δn _L , Δn _L is the linear birefringence of the device under test 511;

(6) Under the premise of not calculating the scanning optical path range S of the common delay component 519, measure the total optical distance L _tr and L _tm of the scanning arm 524 and the transmission arm 525 in the transmission performance test structure 530 of the optical coherence domain polarization measurement technology , calculate the optical path difference S _W2 of light waves between the fast and slow axes, S _W2 = l _W × Δn _W , Δn _W is the linear birefringence of the optical fiber device;

(7) Judging whether the scanning optical path range S introduced by the common delay component 519 satisfies S>L _tm -L _tr and S>S _W2 +S _L , if satisfied, skip step (8) and proceed to step (9) Measurement;

(8) If the condition is not satisfied, then re-intercept the length of the two-arm optical fiber of the transmission performance test structure 530 of the optical coherence domain polarization measurement technology, so that it meets the required conditions in step (7);

(9) Connect the transmission and reflection performance testing device of the optical fiber device, turn on the wide-spectrum light source 501, and test the performance of the optical fiber device;

(10) Utilize the transmission performance of the optical coherent domain polarization measurement technology to test the length relationship of each section of optical fiber in the structure 530, and obtain the information of the polarization crosstalk peak of the optical fiber device;

(11) Utilize the reflection performance of optical low-coherence reflection technology to test the length relationship of each section of optical fiber in the structure 540, and obtain the reflection spectrum of the optical fiber device;

(12) Through comprehensive analysis of crosstalk peaks and reflection peaks, information such as polarization performance, dispersion characteristics, loss characteristics, and coherent spectrum characteristics are obtained, and device testing is completed.

The invention provides a transmission and reflection performance testing device and method of an optical fiber device. Through the joint use of OLCR and OCDP technology, the polarization performance, dispersion characteristics, loss characteristics, and coherent spectrum characteristics of optical fiber devices can be obtained comprehensively. The invention has the advantages of simple construction, simultaneous measurement of transmission and reflection properties of optical fiber devices, and the like, and can be widely used in high-precision optical device performance measuring instruments.

The invention is a device for testing transmission and reflection properties of optical fiber devices based on the principle of white light interference. Combining the two testing technologies of OCDP and OLCR, the characteristics of the transmitted beam and reflected beam of the optical fiber device are tested at the same time. It has the characteristics of high precision, stability and reliability, and comprehensive measurement, and can be used to measure the performance of high-precision optical devices.

1. For the sake of simplicity, the working principle of OCDP is shown in Figure 1, taking the performance test of polarization-maintaining fiber as an example: the highly stable wide-spectrum polarized light 101 emitted by a wide-spectrum light source is injected into the polarization-maintaining fiber 120 of a certain length Slow axis (the principle is similar when injecting into the fast axis). Since not all light is transmitted strictly along the polarization-maintaining axis in a polarizing device, there will be non-ideal defect points or connections. When the signal light is transmitted along the slow axis, when the signal light is transmitted to the defect point 111, a part of the light energy in the slow axis will be coupled into the orthogonal fast axis to form a coupled beam 103, and the remaining transmitted beam 102 is still along the slow axis. shaft transmission. The optical fiber has linear birefringence Δn (take 5×10 ^-4 as an example), so that the refractive index of the slow axis is greater than the refractive index of the fast axis. When the other end of the fiber is output (the transmission distance is l), the transmission at the slow axis An optical path difference Δnl will be generated between the light 102 and the coupled light 103 traveling on the fast axis.

The above-mentioned light beam enters the optical path correlator 130 through the welding point or the rotary joint 112 and the analyzer 113 . In the optical path correlator 130, the polarization beam splitter 131, the Faraday rotation mirror 133, and the moving mirror 136 form a Michelson interferometer. The light beams 102 and 103 enter the fixed arm 132 and the scanning arm 134 after passing through the polarizing beam splitter 131 . The light transmitted in the fixed arm 132 is reflected by the Faraday rotation mirror 133; the light transmitted in the scanning arm passes through the collimating lens 135, is reflected by the moving mirror 136, and the two parts of the light form a white light interference signal in the polarization beam splitter 131, and pass through The photodetector 114 then converts the optical signal into an electrical signal. The signal reaches the detection and signal recording device 140, and is sent to the computer 142 after being processed by the signal demodulation circuit 141; the computer 142 is also responsible for controlling the moving mirror 136 to realize optical path scanning.

Under the control of the computer 142, the moving mirror 136 of the Michelson interferometer makes the optical path difference of the two arms of the interferometer pass through zero from -Δnl and scan to +Δnl, as shown in Figure 2:

(1) When the optical path difference is equal to -Δnl, the light 204 in the scanning arm matches the light 201 in the fixed arm, and a white light interference signal is generated, and the amplitude of the peak value 221 is It is proportional to the coupling magnitude factor of the defect point and the intensity of the light source.

(2) When the optical path difference is equal to 0, in the scanning arm and the fixed arm, the light 205 matches with the light 201, and the light 206 matches with the light 202, then a white light interference signal is generated, and the amplitude of the peak value 222 is I _coupling ∝I ₀ , which Proportional to the intensity of the light source.

(3) When the optical path difference is equal to +Δnl, the light 207 in the scanning arm matches the light 202 in the fixed arm, and a white light interference signal is generated, and the amplitude of the peak value 223 is It is proportional to the coupling magnitude factor of the defect point and the intensity of the light source.

The interference signal is processed, normalized and converted into a dB value. By detecting the amplitude and distance of the interference peak, important information such as the position of the defect of the polarization-maintaining fiber and the extinction ratio can be obtained.

2. The working principle of OLCR is shown in Figure 3: the low-coherence light emitted from the broadband light source 301 passes through the isolator 302, and the light beam is divided into reference light and measurement light at the coupler 303 and enters the reference arm of the interferometer 300 respectively. 306 and measuring arm 304; the reference arm 306 exits through the collimating mirror 307, and the reference light returned by the reference mirror 308 and the measuring light reflected (scattered) from the inside of the device under test 305 merge into the coupler 303 again to interfere, and the two The coherent signal is received by the photodetector 309, and after passing through the signal processing circuit and the computer data acquisition system 310, the performance information of the device under test is obtained. After the signal is processed by the signal demodulation circuit 312, it is sent to the measurement computer 311; the measurement computer 311 is also responsible for controlling the moving mirror 308 to realize optical path scanning.

In the amplitude-sensitive OLCR technology, the measured white light interference envelope peak amplitude is proportional to the reflectivity to be measured, and the scanning position of the envelope peak corresponds to the position of the reflection of the device under test 305 . If the device under test not only includes a single reflective surface, but is formed by a series of spatially independent reflective surfaces, the measurement result is schematically shown in FIG. 4 . The three interference peaks R ₁ , R ₂ and R ₃ in FIG. 4 respectively indicate that large scattering occurs at three different positions in the device under test 305 .

Compared with the prior art, the present invention has the advantages of:

(1) Combined use of OLCR measurement technology and OCDP measurement technology to measure the reflection and transmission properties of fiber optic devices at the same time, such as polarization performance, dispersion characteristics, loss characteristics, coherent spectrum characteristics, etc. of fiber optic devices, to comprehensively evaluate the overall performance of fiber optic devices Test evaluation.

(2) Use the same wide-spectrum light source to improve the utilization rate of the light source output beam and avoid the loss of the transmitted (reflected) beam; use a shared scanning mechanism to achieve simultaneous measurement of transmission and reflection performance and simplify the device.

(3) The structure of simultaneous measurement can avoid the influence of external environment changes on the measurement results when different measuring instruments are used for measurement.

Description of drawings

Figure 1 is a schematic diagram of the optical principle of optical coherent domain polarization measurement technology (OCDP) for the measurement of a single defect point;

Figure 2 is a schematic diagram of the corresponding relationship between the interference signal peak and the attenuation factor of the transmitted light formed by the optical coherent domain polarization measurement technology (OCDP) for the single polarization crosstalk measurement;

Fig. 3 is a schematic diagram of the optical principle of the Optical Low Coherence Domain Reflectometry (OLCR) technology;

Fig. 4 is a schematic diagram of the measurement results of the Optical Low Coherence Domain Reflectometry (OLCR) technique;

Fig. 5 is the structure diagram of transmission and reflection performance testing device 1 of optical fiber device;

Fig. 6 is the structure diagram of the transmission and reflection performance testing device II of the optical fiber device;

Fig. 7 is a flowchart of a method for testing transmission and reflection performance of an optical fiber device.

Detailed ways

In order to clearly illustrate the transmission and reflection performance testing device of the optical fiber device of the present invention, the present invention will be further described in conjunction with the examples and accompanying drawings, but the protection scope of the present invention should not be limited by this.

Fig. 5 and Fig. 6 are two structures of the transmission and reflection performance testing device of the optical fiber device of the present invention. The selection and parameters of the main optoelectronic devices are as follows:

(1) The central wavelength of the adjustable broadband light sources 501 and 601 is 1550nm, the half-spectrum width is greater than 45nm, the fiber output power range is 0-2mW, and the extinction ratio is greater than 6dB;

(2) Single-mode couplers 502, 512, 516, 521, 613, and 617 have an operating wavelength of 1550nm, an extinction ratio greater than 20dB, an insertion loss of less than 0.5dB, and a splitting ratio of 50/50;

(3) The working wavelength of the polarization maintaining couplers 603, 605, and 609 is 1550nm, the extinction ratio is 40dB, the insertion loss is less than 0.5dB, and the splitting ratio is 50/50;

(4) The working wavelength of the polarizers 504, 510, 515, 602, and 612 is 1550 nm, the extinction ratio is 30 dB, and the insertion loss is less than 1 dB;

(5) The working wavelength of the polarization state controllers 505, 520, 616, and 620 is 1550 nm, and the insertion loss is 0.5 dB;

(6) The operating wavelength of the three-port circulators 507, 509, 517, 606, and 614 is 1550nm, the insertion loss is 0.8dB, and the isolation is greater than 50dB;

(7) The operating wavelength of the self-focusing collimating lens 506, 518, 607, 615 is 1550nm, and the optical path scanning distance between it and the double-sided mirror (reflection rate is more than 92%) in the common delay part 519, 608 It varies between 0 and 400mm, and the average insertion loss is 3.0dB;

(8) The photosensitive materials of the detectors 513, 514, 522, 523, 610, 611, 618, and 619 are all InGaAs, and the light detection range is 1100-1700 nm, such as the Nirvana ^TM series 2017 balanced detector of New Focus Company.

In conjunction with Fig. 5, the first embodiment of the transmission and reflection performance testing device of the optical fiber device of the present invention is: a transmission performance testing structure 530 including a broadband light source 501, an optical coherent domain polarization measurement technique (OCDP), an optical low coherence reflection Technology (OLCR) reflective performance test structure 540, detection and signal recording device 550, device under test part 560, is characterized in that: wide-spectrum light source 501 injects light beam into the device under test part 560, wherein the device under test 511 respectively produces The transmitted light beam 560a and the reflected light beam 560b, the transmitted light beam 560a is injected into the OCDP transmission performance test structure 430, the reflected light beam 560b is injected into the OLCR reflection performance test structure 540, and the common delay component 519 is used to scan simultaneously, and the interference light in the two structures The signal is measured, and finally the transmission and reflection characteristics of the optical fiber device under test are obtained simultaneously.

In the OCDP transmission performance testing structure 530, the transmission light beam 560a is analyzed by the first analyzer 515, and then divided into two beams by the first coupler 516, and injected into the OCDP scanning arm 524 and the OCDP transmission arm 525 of the interferometer respectively. , the reference scanning arm is connected to the first collimator lens 518 through the first circulator 517, scanned and reflected through the common delay component 519, and finally the two beams interfere at the second coupler 521, and receive interference signals through the detectors 522 and 523.

l _W is the length of the device under test 511, then the optical path difference S _W2 of light waves between the fast and slow axes (S _W2 = l _W × Δn _W , Δn _W is the linear birefringence of the device under test 511); by the device under test 511 The optical path difference introduced by the fast and slow axes of front and back polarization maintaining fibers s3 and s4 is S _L . For the scanning optical path range S introduced by the common delay component 519, the above parameters need to satisfy:

S>S _W2 +S _L (1)

Under the premise of not calculating the scanning optical path range S of the common delay component 519, in the OCDP transmission performance test structure 530, the total optical paths of the OCDP scanning arm 524 and the OCDP transmission arm 525 are L _tr and L _tm respectively, and the above parameters need to satisfy :

S>L _tm -L _tr (2)

Conditions (1) and (2) make the optical path scanning range S cover the entire range of the optical fiber device, so as to obtain a complete interference spectrum of the transmission performance.

The OLCR reflection performance test structure 540 is divided into two beams by the broadband light source 501 through the third coupler 502: one beam is transmitted in the OLCR transmission arm 503 and enters the device under test 511 by the second circulator 509, and the reflected beam 560b is sequentially Continue to propagate in the OLCR transmission arm 503 via the second circulator 509 and the second analyzer 510; another beam is transmitted as a reference light in the OLCR scanning arm 508, and the reference scanning arm passes through the third circulator 507 and the second collimator lens 506 connection; the last two beams of light interfere at the fourth coupler 512, and receive interference signals through detectors 513 and 514.

The maximum reflected optical path difference generated by the device under test 511 is S _W1 (S _W1 =l _W ×n _W , where n _W is the refractive index of the device under test 511 ). For the scanning optical path range S introduced by the common delay component 519, it must satisfy:

S>S _W1 (3)

On the premise of not calculating the scanning optical path range S of the common delay component 519, in the OLCR reflection performance test structure 540, the respective total optical paths L _cr and L _cm of the OLCR scanning arm 508 and the OLCR transmission arm 503 need to satisfy:

S>L _cm -L _cr (4)

Conditions (3) and (4) make the optical path scanning range S cover the entire range of the optical fiber device, so as to obtain a complete interference spectrum of reflection performance.

The detection and signal recording device 550 is composed of a signal processing unit 551 and a computer terminal 552 .

In the device under test part 560, the test beam utilizes the transmission arm 503 part of the OLCR reflective performance test structure 540: the wide-spectrum light emitted by the wide-spectrum light source 501 passes through the second coupler 503, the polarizer 504, the second The circulator 509 reaches the device under test 511 .

Combining with Figure 7, the measurement method of the transmission and reflection performance test device based on the optical fiber device is as follows:

(1) Measure the length l _W of the optical fiber device 511 to be tested, and calculate the maximum reflected optical path difference S _W1 of the optical fiber device (S _W1 = l _W ×n _W , the refractive index of the n _W optical fiber device).

(2) Without calculating the delay line scanning optical path S, measure the respective total optical paths L _cr and L _cm of the reference scanning arm and the transmission measuring arm in the OLCR reflective performance test structure.

(3) Judging whether the scanning optical path range S introduced by the common delay component 519 satisfies S>S _W1 and S>L _cm -L _cr , and if it is satisfied, proceed to the next step of measurement; if it does not meet the conditions, it is necessary to re-intercept OLCR The length of the two-arm optical fibers of the reflection performance test structure makes it meet the required conditions.

(4) Test the lengths _lWi and _lWo of the input and output pigtails s3 and s4 of the optical fiber device 511 respectively, and test the output optical fiber length _lL9-o of the second circulator 509 and the input optical fiber s7 length of the polarizer 515 l _L15-i , and calculate the optical path difference S _L introduced by the fast and slow axis of the polarization-maintaining fiber (S _L ＝(l _Wi +l _Wo +l _W +l _L9-o +l _L15-i )×Δn _L ，Δn _L linear birefringence in polarization-maintaining fibers).

(5) Without calculating the scanning optical path range S of the movable double-sided mirror, measure the total optical path L _tr and L _tm of the reference scanning arm and the transmission measurement arm in the OCDP transmission performance test structure, and calculate the distance between the fast and slow axes The optical path difference S _W2 of the light wave (S _W2 = l _W × Δn _W , the linear birefringence of Δn _W fiber optic device).

(6) Judging whether the scanning optical path range S introduced by the common delay component 519 satisfies S>L _tm -L _tr and S>S _W2 +S _L , and if it is satisfied, the next step of measurement is carried out; if the condition is not satisfied, then it is required Re-cut the length of the two-arm optical fibers of the OCDP transmission performance test structure to meet the required conditions.

(7) Connect the transmission and reflection performance testing device of the optical fiber device, turn on the wide-spectrum light source 501, and test the performance of the optical fiber device.

(8) Use the lengths of l _L9-o , l _Wi , l _W , l _Wo , and l _L15-i to obtain the information of the polarization crosstalk peak of the optical fiber device.

(9) Use the lengths of l _L9-o , l _Wi , and l _W to obtain reflection peak information of optical fiber devices, and obtain polarization performance, dispersion characteristics, loss characteristics, coherent spectrum characteristics, etc. through comprehensive analysis of crosstalk peaks and reflection peaks information to complete the device test.

Combined with 6, the second embodiment of the transmission and reflection performance testing device of the optical fiber device of the present invention is: the wide-spectrum light source 601 passes through the 45 polarizer 602 and the 1×2 polarization maintaining coupler 603 in sequence, and injects the light beam into the test device In the device 604: the transmitted light beam 660a and the reflected light beam 660b are respectively generated by the device under test 604, the transmitted light beam 660a is injected into the OCDP transmission performance test structure 630, and the reflected light beam 660b is injected into the OLCR reflection performance test structure 640, using a common delay component 608 Carry out simultaneous scanning; measure the interfering light signals in the two structures, obtain the transmission information of the optical fiber device to be tested at the detectors 618 and 619 respectively, and obtain the reflection information of the optical fiber device to be tested at the detectors 610 and 611, and finally obtain the The signal is analyzed at recording device 650 .

Its measurement method is as follows:

(1) Measure the length l _W of the optical fiber device 604 to be tested, and calculate the maximum reflected optical path difference S _W1 of the optical fiber device (S _W1 = l _W ×n _W , the refractive index of the n _W optical fiber device).

(2) Under the premise of not calculating the delay line scanning optical path S, the reflection measurement arm of the OLCR reflection performance test structure includes the a1 end and a3 end of the 1×2 coupler 603, the a2 end of the optical fiber device to be tested, and the three-port ring The 3-section pigtail of the device 606, the self-focusing lens 607, the movable double-sided mirror in the common delay part 608, the polarization state controller 620, the a6 end of the 2×2 coupler 609; the reference arm of the OLCR reflective performance test structure It includes terminal a1 and terminal a3 of 1×2 coupler 603 , terminal a2 and terminal a7 of the optical fiber device to be tested, terminal a8 and terminal a9 of 1×2 coupler 605 , and terminal a10 of 2×2 coupler 609 . The total optical distances of the reference arm and the reflection measurement arm in the test structure for measuring OLCR reflection performance are L _cr and L _cm , and the two paths of interference light pass through the 2×2 coupler 609 to form an interference signal, which is detected by detectors 610 and 611 .

(3) Judging whether the scanning optical path range S introduced by the movable double-sided mirror in the common delay component 608 satisfies S>S _W1 and S>L _cm -L _cr , and if it is satisfied, proceed to the next step of measurement; if not If the conditions are met, it is necessary to re-cut the length of the two-arm optical fibers of the OLCR reflection performance test structure to meet the required conditions.

(4) Test the lengths of the input and output pigtails a2 and a7 of the optical fiber device 604 respectively _lWi and _lWo , and test the length _lL5-o of the output fiber of the 1×2 polarization coupler 605 and the input fiber of the polarizer 612 a11 length l _L12-i , and calculate the optical path difference S _L introduced by the fast and slow axis of the polarization maintaining fiber (S _L =(l _Wi +l _Wo +l _W +l _L5-o +l _L12-i )×Δn _L , Δn _L the linear birefringence of a polarization-maintaining fiber).

(5) Without calculating the scanning optical path range S of the movable double-sided mirror, the OCDP transmission performance test structure consists of a 1×2 polarization coupler 613, a three-port circulator 614, a self-focusing lens 615, and a common delay component 608 The movable double-sided mirror, the polarization state controller 616, and the 2×2 coupler 617 are constituted. Measure the total optical path L _tr and L _tm of the reference scanning arm and the transmission measuring arm in the OCDP transmission performance test structure, and calculate the optical path difference S _W2 of the light wave between the fast and slow axes (S _W2 = l _W × Δn _W , Δn _W fiber optic device linear birefringence).

(6) Judging whether the scanning optical path range S introduced by the movable double-sided mirror in the common delay component 608 satisfies S>L _tm -L _tr and S>S _W2 +S _L , if it meets the test, proceed to the next step of measurement ; If the conditions are not met, it is necessary to re-cut the lengths of the two-arm optical fibers of the OCDP transmission performance test structure to meet the required conditions.

(7) Connect the transmission and reflection performance testing device of the optical fiber device, turn on the wide-spectrum light source 601, and test the performance of the optical fiber device.

(8) Use the lengths of l _L9-o , l _Wi , l _W , l _Wo , and l _L15-i to obtain the information of the polarization crosstalk peak of the optical fiber device.

(9) Use the lengths of l _L9-o , l _Wi , and l _W to obtain reflection peak information of optical fiber devices, and obtain polarization performance, dispersion characteristics, loss characteristics, coherent spectrum characteristics, etc. through comprehensive analysis of crosstalk peaks and reflection peaks information to complete the device test.

Claims (4)

1. a kind of transmission of optical fibre device and reflecting properties test device, it is characterized in that：Including wide spectrum light source (501), optics phase The reflection of the transmission performance test structure (530), optics Low coherence reflection technology (OLCR) of dry domain polarimetry technology (OCDP) Performance test structure (540), detection and signal recording apparatus (550), device under test part (560), wide spectrum light source (501) is by light In beam injection device under test part (560), the device under test (511) in device under test part (560) generates transmitted light beam respectively (560a) and the reflected beams (560b), the transmission performance test of transmitted light beam (560a) injection optics coherent field polarimetry technology The reflecting properties test structure (540) of optics Low coherence reflection technology is injected into structure (530), by the reflected beams (560b) In, it is scanned, the interference light signal in two structures is measured, simultaneously simultaneously using shared delay unit (519) progress finally Obtain transmission and the reflectance signature of testing fiber device.

2. the transmission of optical fibre device according to claim 1 and reflecting properties test device, it is characterized in that the optics phase The transmission performance test structure (530) of dry domain polarimetry technology includes：Transmitted light beam (560a) passes through the 1st analyzer (515) After analyzing, two beams are divided by the 1st coupler (516), are injected separately into the transmission performance test of optical coherence domain polarimetry technology The scan arm (524) of structure is with transmiting in arm (525), and the scan arm is by the 1st circulator (517) and the 1st collimation lens (518) connect, by sharing delay unit (519) scanning reflection, last two-beam is interfered in the 2nd coupler (521), is passed through Cross the first detector (522), the second detector (523) receives interference signal.

3. the transmission of optical fibre device according to claim 1 or 2 and reflecting properties test device, it is characterized in that the optics The reflecting properties test structure (540) of Low coherence reflection technology includes：Wide spectrum light source (501) is divided by the 3rd coupler (502) Two beams, the transmission arm (503) of a branch of reflecting properties test structure in Low coherence reflection technology are transmitted by the 2nd circulator (509) Into device under test (511), the reflected beams (560b) continue via the 2nd circulator (509), the 2nd analyzer (510) low successively The transmission arm (503) of the reflecting properties test structure of coherent reflection technology is propagated；Another beam is used as to be reflected with reference to light in Low coherence Scan arm (508) transmission of the reflecting properties test structure of technology, scan arm are saturating by the 3rd circulator (507) and the 2nd collimation Mirror (506) connects；Last two-beam is interfered in the 4th coupler (512), passes through the 3rd detector (513), the 4th detector (514) interference signal is received.

4. a kind of test method of transmission and reflecting properties test device based on optical fibre device described in claim 1, special Sign is：

(1) the length l of device under test (511)_WIt measures, calculates the maximum reflection optical path difference S of device under test (511)_W1, S_W1 =l_W×n_W, n_WFor the refractive index of device under test (511)；

(2) on the premise of delay line scanning light path S is not calculated, the reflecting properties test knot of measurement optics Low coherence reflection technology The respective total optical path L of scan arm (508) and transmission arm (503) in structure (540)_c-rAnd L_c-m；

(3) whether the scanning light path scope S introduced to sharing delay unit (519) meets S>S_W1And S>L_c-m-L_c-rJudged, If it is satisfied, skip over the measurement that step (4) carries out step (5)；

(4) if being unsatisfactory for condition, the two of the reflecting properties test structure (540) of optics Low coherence reflection technology is intercepted again Arm fiber lengths make it meet required condition in step (3)；

(5) device under test (511) preceding polarization maintaining optical fibre (s3), the length of rear polarization maintaining optical fibre (s4) are tested respectively, are denoted as l_W-i、l_W-o, calculate by the optical path difference S of the fast and slow axis introducing of polarization maintaining optical fibre_L, S_L=(l_W-i+lW-o)×Δn_L, Δ n_LFor device under test (511) linear birefrigence；

(6) on the premise of not calculating and can share delay unit (519) scanning light path scope S, measurement optical coherence domain polarization is surveyed The total optical path L of scan arm (524) and transmission arm (525) in the transmission performance test structure (530) of amount technology_t-rAnd L_t-m, calculate The optical path difference S of light wave between fast and slow axis_W2, S_W2=l_W×Δn_W, Δ n_WFor the linear birefrigence of optical fibre device；

(7) whether the scanning light path scope S that couple can share delay unit (519) introducing meets S>L_t-m-L_t-rAnd S>S_W2+S_LIt carries out Judge, if it is satisfied, skipping over the measurement that step (8) carries out step (9)；

(8) if being unsatisfactory for condition, the transmission performance test structure (530) of optical coherence domain polarimetry technology is intercepted again Two-arm fiber lengths, it is made to meet required condition in step (7)；

(9) transmission to optical fibre device and reflecting properties test device are attached, and wide spectrum light source (501) are opened, to optical fiber device The performance of part is tested；

(10) closed using the length of each section of optical fiber in the transmission performance test structure (530) of optical coherence domain polarimetry technology System obtains the information at the polarization interference peak of optical fibre device；

(11) using the length relation of each section of optical fiber in the reflecting properties test structure (540) of optics Low coherence reflection technology, obtain Obtain the reflection collection of illustrative plates of optical fibre device；

(12) by the comprehensive analysis to crosstalk peak and reflection peak, polarization property, dispersion characteristics, loss characteristic, coherent light are obtained The information such as spectral property complete device detection.